U.S. Measles Cases Reach 4,080, CDC Says, Far Past All of 2025

The CDC's tally has reached 4,080 confirmed measles cases for 2026, according to data the agency updated Friday, Oct. 9, reflecting cases reported as of noon Thursday, Oct. 8.

That far surpasses the 2,289 cases confirmed in all of 2025, which was itself the most in three decades. In 2024, the CDC counted 285.

What the CDC numbers show

Of the 4,080 cases, 4,062 were reported by 47 jurisdictions, including Washington, D.C., and New York City. Another 18 were among international visitors.

The spread is driven by outbreaks. The CDC counts 42 new outbreaks in 2026, and 96% of confirmed cases (3,897 of 4,080) are outbreak-associated. Of those, 2,513 come from outbreaks that began this year and 1,384 from outbreaks that started in 2025.

The 2025 comparison: 48 outbreaks, with 90% of cases tied to them. In 2024, 16 outbreaks accounted for 69%.

Most 2026 cases are in children and teenagers 19 and younger, per the CDC. About one in 10 children under 5 has been hospitalized.

The agency says its figures include only confirmed cases that jurisdictions have notified it about. It acknowledges that jurisdictions are also reporting probable cases that are not in the count.

Pennsylvania remains the center

The state's outbreak, which began in late April, stood at 943 cases across 39 counties with 176 hospitalizations as of the Pennsylvania Department of Health's Sept. 30 update. The Democratic National Committee says the outbreak has since passed 1,000 cases.

On Sept. 30, the department reported the death of an unvaccinated Lancaster County resident, the fifth measles-associated death the state has recorded this year. It declined to release the person's identity, saying families "deserve the dignity to mourn in private."

Only four of the 943 patients in that count, under 1%, had been vaccinated. The department says death occurs in one to three of every 1,000 cases and that nearly 20% of people it has identified with measles have been hospitalized.

Pennsylvania also reports a surge in vaccinations. Providers there averaged about 25,000 MMR doses a month before the outbreak. That rose to 49,000 in August and passed 53,000 in September. State nurses have given more than 8,500 MMR doses in 2026, including more than 5,500 at 180 clinics in affected communities.

The department says two doses of MMR provide 97% lifetime protection.

Two death counts

The federal and state numbers do not match. Pennsylvania health officials count five measles-associated deaths this year, all in the state. The CDC has recognized two and says that "number is subject to change."

The two use different criteria. The CDC attributes a death to measles only when the National Center for Health Statistics lists the disease as the underlying cause on the death record. Pennsylvania counts a death when it occurs within 30 days of symptom onset in someone with a positive measles test, unless the death is from an unrelated cause such as a car crash. County coroners challenged how some of the state's five deaths were labeled. Pennsylvania Health Secretary Dr. Debra Bogen stood by both as measles-associated deaths and pressed the CDC to list the deaths the state had reported. Health Secretary Robert F. Kennedy Jr. has backed the county-level findings over the state's reporting, which he called premature.

The CDC says it is working with the Council of State and Territorial Epidemiologists to develop a standardized case definition for measles deaths.

For comparison, three measles deaths were reported in 2025, two in Texas and one in New Mexico, all in unvaccinated people.

The political fight

Democrats are using the milestone against the administration. Rep. Lauren Underwood, D-Ill., a registered nurse, said in a statement that "Donald Trump and RFK Jr. have needlessly put American children and families at risk of serious illnesses that were once eliminated." She said the administration is "making it harder for parents to find and trust safe and proven medical advice."

The Democratic statement cites several administration actions. It points to the CDC advisory panel Kennedy hand-selected, which eliminated recommendations for the combined MMRV vaccine for children under 4 and ended the universal hepatitis B recommendation for newborns. It also cites a September executive order signed by Trump changing the childhood vaccine schedule, which the statement says experts warn could lead to more preventable illness.

The statement also claims Kennedy downplayed the severity of the Pennsylvania deaths and claimed the cure for measles is chicken soup and vitamin A. The statement asserts that Trump and Kennedy have presided over more measles cases since taking office than the previous 30 years combined, a comparison the CDC's own figures do not make. The CDC says only that 2025 was the worst year in three decades and that 2026 has already surpassed it.

What comes next

The Democratic statement says New York Gov. Kathy Hochul declared a statewide disaster emergency this week and that Wisconsin has reported more than 250 cases this year. Both are figures from that statement, not from the CDC.

The open question is the death toll. Pennsylvania counts five measles-associated deaths this year, while the CDC has recognized two. The CDC says its number is subject to change as additional information becomes available and relevant reviews are completed.